Raimon @ quifisraimon
df7ba3a02a
- [NEW] Registres d'escritura del TIA: Implementats VSYNC, VBLANK, WSYNC i RSYNC
104 lines
2.7 KiB
C++
104 lines
2.7 KiB
C++
#include "tia.h"
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namespace tia
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{
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uint8_t collisions[8] { 0, 0, 0, 0, 0, 0, 0, 0 };
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float paddle_pos[4] { 0.5f, 0.5f, 0.5f, 0.5f };
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uint32_t paddle_charge_cycles[4] { 0, 0, 0, 0 };
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bool joy0_button_pressed = false;
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bool joy1_button_pressed = false;
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uint32_t current_frame_cycles = 0;
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bool vsync_set = false;
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bool vblank_set = false;
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bool vblank_latch = false;
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bool vblank_dump = false;
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uint16_t color_clock = 0;
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bool rdy_low = false;
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void reset()
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{
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}
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void tick()
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{
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if (!vblank_dump) current_frame_cycles++;
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color_clock = (color_clock + 1) % 228;
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if (color_clock == 0) rdy_low = false;
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// [TODO] Pintar pixels
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}
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uint8_t get_paddle_state(int index)
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{
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if (vblank_dump) return 0x00;
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return (current_frame_cycles >= paddle_charge_cycles[index]) ? 0x80 : 0x00;
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}
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uint8_t read(uint16_t address)
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{
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switch (address & 0x0f) {
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case 0x00: return collisions[0];
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case 0x01: return collisions[2];
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case 0x02: return collisions[3];
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case 0x03: return collisions[4];
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case 0x04: return collisions[5];
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case 0x05: return collisions[6];
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case 0x06: return collisions[7];
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case 0x07: return collisions[8];
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case 0x08: return get_paddle_state(0);
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case 0x09: return get_paddle_state(1);
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case 0x0A: return get_paddle_state(2);
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case 0x0B: return get_paddle_state(3);
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case 0x0C: return joy0_button_pressed ? 0x00 : 0x80;
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case 0x0D: return joy1_button_pressed ? 0x00 : 0x80;
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}
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}
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void write(uint16_t address, uint8_t value)
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{
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address &= 0x3f;
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if (address >= 0x2d) address -= 0x20;
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// [TODO] Procesar segons l'adreça resultant
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switch (address) {
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case 0x00: // VSYNC
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vsync_set = value & 0x20;
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break;
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case 0x01: // VBLANK
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bool prev_dump = vblank_dump;
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vblank_set = value & 0x20;
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vblank_latch = value & 0x40;
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vblank_dump = value & 0x80;
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if (prev_dump && !vblank_dump) {
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current_frame_cycles = 0;
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for (int i = 0; i < 4; ++i) paddle_charge_cycles[i] = static_cast<uint32_t>(paddle_pos[i] * 2400.0f);
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}
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break;
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case 0x02: // WSYNC
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rdy_low = true;
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break;
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case 0x03: // RSYNC
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color_clock = 0;
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break;
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}
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}
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bool is_rdy_low()
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{
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return rdy_low;
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}
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}
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